[zmd94]

Try below:

#include <amxmodx>

#define TASK_TEAM 2017
new g_iCount[33] 

new const MAX_TIME = 30 
new const WORD_KICK[] = "Do not choose a team"

public plugin_init() 
{ 
	register_plugin("No Team Unassigned", "1.0", "zmd94")
	register_event("TeamInfo", "fwPlayerJoinedTeam", "a") 
}

public client_putinserver(id) 
{ 
	if(is_user_connected(id))
	{
		g_iCount[id] = MAX_TIME
		set_task(1.0, "CheckTeam", id+TASK_TEAM, _, _, "b")
	}
}

public CheckTeam(id) 
{
	id -= TASK_TEAM
	if(is_user_connected(id))
	{
		g_iCount[id]--
		if(g_iCount[id] == 0) 
		{
			server_cmd("kick #%d ^"%s^"", get_user_userid(id), WORD_KICK) 
		}
		
		client_print(id, print_center, "You have %d s to choose a team", g_iCount[id]) 
	}
}

public fwPlayerJoinedTeam() 
{ 
	new id = read_data(1)
	if(is_user_connected(id)) 
	{
		static sUserTeam[32]
		read_data(2, sUserTeam, charsmax(sUserTeam)) 
		
		switch(sUserTeam[0])
		{
			case 'C':  
			{
				// player join to ct's    
				remove_task(id+TASK_TEAM) 
				g_iCount[id] = 0 				
			}
			case 'T': 
			{
				// player join to terrorist
				remove_task(id+TASK_TEAM) 
				g_iCount[id] = 0 
			}
			case 'S':  
			{
				// player join to spectators
				// Do nothing?
			}
		}
	} 
}

public client_disconnect(id) 
{
	g_iCount[id] = 0 
	remove_task(id+TASK_TEAM) 
}